Sheet feeding mechanism



H. E. KELCHNER SHEET FEEDING MECHANISM Jan. 8, 1963 Filed NOV. 18, 1959 INVENTOR. HARLEY E. KELCHNER ATTORNEY United States Patent M 3,072,397 SHEET FEEDING MECHANISM Harley E. Kelchner, King of Prussia, Pa., assignor to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Filed Nov. 18, 1959, Ser. No. 853,950 2 Claims. (Cl. 271-53) This invention relates generally to sheet feeding apparatus and more particularly to improvements in sheet feeding rollers and associated devices for feeding thin flexible sheet items such as, for example, paper bank checks.

In certain types of sheet feeding equipment individual sheets are fed from a supply station directly to an operating mechanism for the performance of some operation on or with respect to the sheets. Such a mechanism, for example, might be a printing machine in which case the individual sheets are fed directly from a hopper through a delivery path to the printing platen of the machine.

It has been found advantageous from a time-saving point of view to shorten the delivery path from the supply hopper to the operating mechanism by moving the sheets individually and successively from the hopper to an advance or ready position before they are delivered to the operating mechanism and to hold each successive sheet at the ready position until it is called for at the operating mechanism. This preliminary movement of the individual sheets is accomplished without any time loss since it is performed while a previous sheet is being processed in the operating mechanism. Accordingly, the final movement of delivering the advanced sheets to the operating mechanism overthe shortened path is accomplished with a considerable saving in time.

An object of the invention therefore is to provide a sheet feeding mechanism enabling a moving sheet to be stopped at a predetermined position without harm to the sheet.

Another object of the invention is to provide such a mechanism which Will instantaneously feed the sheet toward its destination Whenever the sheet is released for movement.

In accordance with the above objects and first briefly considered in its broad aspects, the invention comprises a feed roller which will stop rotating independently of its continuously operating drive whenever a sheet is stopped while in the grip of the roller and which will commence rotating to feed the sheet whenever the sheet is released for movement.

The invention will be more clearly understood when the following detailed description of specific embodiments thereof are read in conjunction with the accompanying drawings in which:

FIG. 1 is a sectional view of a sheet feeding apparatus embodying the invention;

FIG. 2 is a transverse sectional view taken along line 22 of FIG. 1; and 6 FIG. 3 illustrates the invention in a modified form.

Referring to FIGS. 1 and 2 of the drawings, one embodiment of the invention comprises a platen 10 having depending lugs 12, only one of which is shown, which are pivotally mounted on a fixed pin 14. The platen 10 is biased in a counterclockwise direction to exert pressure against a feed roller 16 by means of a compression spring 18.

The roller 16 is rotatably mounted on a drive shaft 20 which is rotated from a source of power such as an electric motor, not shown. The roller 16 comprises a hub 22 and a plurality of tires 24, such for example, as rubber, secured thereto. The hub 22 may be constructed of any suitable wear-resistant material, however, good results have been obtained by constructing it of nylon.

3,072,397 Patented Jan. 8, 1963 Secured on the drive shaft 20 is a stop collar 26. A pair of friction clutch discs 28 and 30 are slidably mounted on the shaft and co-act with the end faces of the hub 22 to provide a friction drive for transmitting rotation to the roller 16 from the drive shaft 20. The discs 28 and 30 are rotated by the drive shaft 20 by means of driver pins 36 and 38 secured to the shaft and engaged in diametrically opposed key ways 32 and 34 in each disc. A compression spring 40 is suitably adjusted by means of a collar 42 to exert the proper degree of force against a thrust washer 44 loosely mounted on the drive shaft 20 for obtaining the desired friction force between the discs 28 and 30 and the hub 22.

Below the platen 10 and similarly mounted is a stop gate 46 having depending lugs 48 at one end, only one of which is shown, which are pivotally mounted on a fixed pin 50. The stop gate 46 is urged in a counterclockwise direction about the pin 50 by means of a compression spring 52 and against a fixed stop member 54. In this position of the stop gate 46, an upwardly extending flange 56 thereof extends through an aperture 53 in the platen 10 and into the path of movement of a sheet S.

In operation, and before a sheet is delivered to the roller 16, the platen 10 is pressing directly against the roller and holding it stationary in opposition to the driving torque of the discs 28 and 30. When a sheet S is fed across the platen 10 in the direction of the arrow shown in FIG. 2, by means of associated apparatus, not shown, and enters into the nip of the roller 16 and the platen 10 it will urge the platen downwardly away from the roller which will then be free to rotate and feed the sheet against the flange 56 of the stop gate. When the sheet S stops against flange 56 the roller 16 will then stop rotating while continuing to urge the sheet forward. This condition of the roller 16 is obtained by properly balancing the forces between the springs 18 and 4'0 so that slipping occurs between the discs 28 and 30 and the hub 22. It is understood that due to certain conditions such as vibration or variations in texture of the surface of the sheets the roller 16 may rotate slightly and experience a minimum amount of skidding on a particular sheet whenthe sheet is stopped by the flange 56.

When it is desired to deliver the sheet S to its destination the stop gate 46 is rocked clockwise against the biasing action of spring 52, by any suitable means such as by energizing an electromagnet 60, to withdraw the flange 56 from the path of the sheet at which time the roller 16 will respond to the torque exerted by discs 28 and 39 on hub 22 and instantly accelerate and feed the sheet across the platen 10 toward its delivery point.

A modification of the invention is shown in FIG. 3 in which the platen 10 is stationary and its previous function of exerting pressure against the roller 16 is now performed by means of a pressure roller 62 rotatably mounted on a pin 64 fixed to one end of a lever 66 rockably mounted on a fixed pin 68. The roller 62 is biased against the roller 16 by means of a tension spring 79 connected tothe opposite end of the lever 66. In this embodiment of the invention, when there is no sheet in the nip of the rollers 16 and 62, the roller 16 continues rotating and accordingly rotates the roller 62 with it. However, when a sheet S is delivered into the nip of the rollers and is fed to and stopped by the flange 56' the action of the roller 16 will be the same as explained above, that is, it will either stop or experience a minimum amount of skidding while continuing to urge the sheet S forward.

In a similar manner, as explained above, when the gate stop 46 is rocked counterclockwise by energizing an electromagnet to withdraw the flange 56' out of the path of sheet feeding, the sheet S will be fed ina stantaneously by the rollers 16 and 62 across the platen 10' toward its destination.

From the above description it will now be seen that the invention provides improvements in sheet feeding mechanisms whereby a moving sheet may be brought to a stop at a predetermined position and instantaneously fed away whenever delivery of the sheet is called for.

While there have been disclosed specific embodiments of the invention, it is to be understood that the invention is capable of being constructed in a variety of sizes,

shapes and forms without departing from the true spirit and scope thereof. Accordingly it is the intention not to be limited by the specific devices disclosed but only by the subjoined claims.

What is claimed is:

1. A mechanism for feeding thin flexible paper sheets comprising, a rotatable drive shaft of uniform diameter throughout its length, a feed roller rotatably mounted on the drive shaft for frictionally feeding a sheet by a surface of the sheet which is parallel to the direction of feeding, a clutch disc slidably mounted on said drive shaft, spring means urging said clutch disc into contact with a face of said roller to frictionally couple the roller to said drive shaft, flat platen constructed to support and guide a sheet in a straight line, a spring member pressing said platen against the roller for feeding sheets therebetween by rotaiton of the roller, 21 movable stop member for arresting movement of a sheet, while it is being fed along said platen and its said surface is in the grip of said roller and said platen, said stop 1 member being arranged for movement in a region closely adjacent to the periphery of said roller, and means for moving said stop member into and out of the path of movement of said sheet, the forces of said spring means and spring member being so related that in the abthroughout its length, a feed roller rotatably mounted on the drive shaft for frictionally feeding a sheet by a surface of the sheet which is parallel to the direction of feeding, a clutch disc slidably mounted on said drive shaft, spring means urging said clutch disc into contact with a face of said roller to frictionally couple the roller to said drive shaft, a fiat platen constructed to support and guide a sheet in a straight line, a spring member pressing said platen against the roller for feeding sheets therebetween by rotation of the roller, a movable stop member for arresting movement of a sheet, while it is being fed along said platen and its said surface is in the grip of said roller and said platen, said stop member being arranged for movement in a region closely adjacent to the periphery of said roller, means for moving said stop member into the path of movement of said sheet, and means for moving said stop member out of said path of movement of said sheet, one of said last two means being mechanical and the other being electrical, and the forces of said spring means and spring member being so related that in the absence of a sheet said feed roller will be held against rotation by said platen While said drive shaft continues rotation.

References Cited in the file of this patent UNITED STATES PATENTS 650,410 Morin May 29, 1900 1,286,714 Moore Dec. 3, 1918 1,290,509 Chandler Jan. 7, 1919 1,718,225 Funk June 25, 1929 2,101,268 Novick Dec. 7, 1937 2,156,049 Boerger Apr. 25, 1939 2,394,577 Wise Feb. 12, 1946 2,613,598 McKay Oct. 14, 1952 2,677,542 Backhouse et a1. May 4, 1954 2,711,237 Wylie June 21, 1955 2,757,928 Thomas Aug. 3, 1956 2,964,994 Adler Dec. 20, 1960 

2. A MECHANISM FOR FEEDING THIN FLEXIBLE PAPER SHEETS COMPRISING, A ROTATABLE DRIVE SHAFT OF UNIFORM DIAMETER THROUGHOUT ITS LENGTH, A FEED ROLLER ROTATABLY MOUNTED ON THE DRIVE SHAFT FOR FRICTIONALLY FEEDING A SHEET BY A SURFACE OF THE SHEET WHICH IS PARALLEL TO THE DIRECTION OF FEEDING, A CLUTCH DISC SLIDABLY MOUNTED ON SAID DRIVE SHAFT, SPRING MEANS URGING SAID CLUTCH DISC INTO CONTACT WITH A FACE OF SAID ROLLER TO FRICTIONALLY COUPLE THE ROLLER TO SAID DRIVE SHAFT, A FLAT PLATEN CONSTRUCTED TO SUPPORT AND GUIDE A SHEET IN A STRAIGHT LINE, A SPRING MEMBER PRESSING SAID PLATEN AGAINST THE ROLLER FOR FEEDING SHEETS THEREBETWEEN BY ROTATION OF THE ROLLER, A MOVABLE STOP MEMBER FOR ARRESTING MOVEMENT OF A SHEET, WHILE IT IS BEING FED ALONG SAID PLATEN AND ITS SAID SURFACE IS IN THE GRIP OF SAID ROLLER AND SAID PLATEN, SAID STOP MEMBER BEING ARRANGED FOR MOVEMENT IN A RE- 